The National Museum of Transportation (that 'National' is a designation it gave itself) near St Louis is certainly one of the biggest, covering 42 acres of rolling land with exhibits of cars, wagons, trains, trucks and nearly anything else that can move people or freight. In fact, it claims to be "the largest collection of its kind in the world.
But for today, the trains. It's where the museum started in 1944, and it has on its premises the West Barretts Tunnel first rail tunnel operated west of the Mississippi, as well as over 70 locomotives, many of them sole survivors of their type. The collection starts even earlier than the tunnel; the Boston & Providence car from the 1830s looks like a stagecoach but ran on rails.
Here's a mule-drawn street railway car from the 1870s; it ran in a St Louis suburb until it was replaced by electric trolleys.
Which raises another point: Rail museums are very different from car museums. No matter how old the cars might be, they're not as old as the oldest rail equipment. And, car museums often have models right up to the present, while, sadly, rail museums are almost necessarily about "the old days," at least in the U.S. Trains are still around, but they don't have the same kind of excitement or fanbase.
And, not to put too fine a point on it, the number of museums with the space and the funds to restore and display such huge items is limited indeed. The size of NMoT's collection is extraordinary, but sadly many of the locomotives, cars, trams and more face a very long wait for funds to restore them.
Below, my all-time favorite locomotive, the great electric GG-1 that used to take me on regular trips between New York and Washington, is barely recognizable. A product of the late 1930s, it left service in the 1970s and 80s. Below it, others await their turn as well.
I've noticed that most rail museums I've visited pay the most attention to the locomotives, and this one was no exception, although it has quite a variety of passenger and freight cars in its various sheds and sidings, as well as a giant snowblower.
Aside from the rolling stock, there are also collections of railroadiana and railfan nostalgia; a miniature train to ride around the campus and a number of model railroad setups and play spaces for young children.
The 'Rainbow Locomote' isn't one of the kid exhibits, though: it is color-coded as a teaching tool. Another teaching tool in the collection is a cut-away version of a Union Pacific diesel-electric locomotive.
And then there are the true uniques: a collection of special-purpose vehicles made for different owners. First, a gas-turbine-powered model for the Army; it was used on several bases to haul equipment. The St Louis Water Division mini-locomotive was originally powered by a gasoline engine and later dieselized.
Next up, a commuter 'dinky bus' that ran on commuter rails in Illinois, and a 'doodlebug,' used by track crews.
Several trolley cars of different vintages take visitors on a loop around the railroad display area.
The National Museum of Transportation is at Kirkwood, a suburb of St Louis; if you're a real fan, it can be an all-day excursion including the automobile and other exhibits, but there's enough there to spread it out over two or three visits.
A last treat: the magnificent failure—the Aerotrain, GM's attempt to re-invent commuter railroads with a streamlined engine and cars that were basically bus bodies.